when apt-get install libqt* unmet dependency.
there is a long list of unmet dependency. Where start first and any command to install virtualbox fluently?

You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
virtualbox-4.1 : Depends: libcurl3 (>= 7.16.2-1) but it is not going to be installed
Depends: libqt4-network (>= 4:4.5.3) but it is not going to be installed
Depends: libqt4-opengl (>= 4:4.7.0~rc1) but it is not going to be installed
Depends: libqtcore4 (>= 4:4.7.0~beta1) but it is not going to be installed
Depends: libqtgui4 (>= 4:4.7.0~beta1) but it is not going to be installed
Recommends: libsdl-ttf2.0-0 but it is not going to be installed
Recommends: dkms but it is not going to be installed
Recommends: libhal1 (>= 0.5) but it is not going to be installed
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

Note: Ubuntu/Debian users might want to install the dkms package to ensure that the VirtualBox host kernel modules (vboxdrv, vboxnetflt and vboxnetadp) are properly updated if the linux kernel version changes during the next apt-get upgrade. For Debian it is available in Lenny backports and in the normal repository for Squeeze and later. The dkms package can be installed through the Synaptic Package manager or through the following command: